GREENVILLE, South Carolina (CNN) -- If you were John McCain's chief campaign advisor, you probably wouldn't outline the following strategy for winning the New Hampshire primary: Run to the left of your chief opponent on taxes in a famously anti-tax state. Fail to win the endorsement of a single major Republican office-holder. Air no attack ads. Neglect traditional get-out-the-vote organizing efforts in favor of riding around in a bus all day eating doughnuts with reporters.

As it turned out, of course, McCain's strategy -- whatever it was -- worked
brilliantly.

McCain not only demolished George W. Bush at the polls, he
established himself as a real candidate, someone with a chance of actually
becoming president. During his months in New Hampshire, McCain religiously
avoided pondering his future after February 1. Now that his campaign has
relocated to South Carolina, McCain is coming to believe he could win the
nomination.

He may be right.

McCain knows he will never outspend the Bush campaign. But McCain strategists
are betting their candidate is capable of withstanding the inevitable barrage
of rough Bush ads to come.

As Mike Murphy, McCain's chief strategist, puts
it: "If someone drops a piano on you, it hurts. But if someone drops seven more pianos on you, it doesn't hurt seven times as much." In other words,
Bush will only be able to inflict so much damage with a paid media campaign.
McCain should be able to deflect much of it by using the enormous amount of
free publicity he'll be receiving after New Hampshire.

McCain also mentioned the address of his Web site in every election-night interview he gave. He looked slightly embarrassed as he did it, but the self-promotion paid off. In the first 90 minutes after his victory speech, McCain's site took in about $25,000 in contributions. By the end of the night, supporters had pledged more than $200,000. Until the New Hampshire upset, McCain had been raising about $20,000 a day.

McCain's greatest challenge remains one of perception. George W. Bush has
dominated the race to this point in great measure because Republican donors
believe he is capable of taking back the White House, and preventing the loss
of Congress. The New Hampshire primary may have shaken that faith, and McCain
aims to take advantage of it.

This week, the McCain campaign put up an ad in the seacoast region of South Carolina that features a recent USA Today poll showing McCain beating Al Gore in a theoretical match-up this fall. Rep. Mark Sanford of Charleston appears on camera to make the point as explicitly as possible: "He can win," Sanford says.

Will voters believe it? McCain's moderate politics may help him make the
case. Gore media strategists have been planning for months to attack George W.
Bush in the general election as a wild-eyed, right-wing extremist.

As it happens, Bush is no right-winger, but portions of his record in Texas may
make the attacks plausible. McCain, by contrast, is bulletproof on the
issue. No one will accuse McCain of being a John Birch sympathizer. Indeed,
it's hard to know what Gore could accuse McCain of.